The president was due to land in Delhi at 11:00 (05:30 GMT) and meet Mr Singh at his residence before flying south to Ajmer and then returning to Islamabad in the evening.

Pilgrimage spot

Relations between the two countries have been gradually improving since peace talks were derailed after the Mumbai attacks in 2008.

Mr Zardari recently backed the lifting of trade restrictions on India, and Pakistan is also talking of dropping a restrictive list of what products it will buy from India.

But tensions remain over more sensitive issues, such as the disputed region of Kashmir, and Pakistani militant activity against India.

Only this week, India again called for Pakistan to hand over Hafiz Saeed, the man it alleges planned the Mumbai attacks, after Washington announced a $10m bounty for his arrest.

Pakistan has again refused, asking to see proof for the allegations.

Correspondents say few expect any headway with these issues during Mr Zardari's visit.

The BBC's Andrew North in Delhi says it used to be cricket that gave Indian and Pakistani leaders the cover they need to meet.

The last time a Pakistani leader met Mr Singh was in 2005 when then Pakistan President Pervez Musharraf happened to be at the same cricket match as the Indian prime minister in Delhi, our correspondent says.

The shrine of Sufi saint Moinudin Chishti is one of the most popular pilgrimage sites in the region, receiving a constant flow of devotees.